Numerous valve units have been developed for controlling flow of liquids and gases, and poppet-type valve units are commonly utilized for this purpose. Such valve units commonly employ a shiftable valve having an annular poppet thereon, which poppet is conventionally of elastomeric construction and cooperates with an annular valve seat provided on the valve unit housing. U.S. Pat. Nos. 4,971,115 and 4,915,134, both owned by the Assignee hereof, illustrate prior four-way and three-way poppet valves which have been developed for controlling fluid flow, and which have been demonstrated to possess desirable constructional and operational features. However, in an ongoing attempt to still further improve upon the performance of such poppet-type valve units, additional improvements have been made in the poppet configuration and constitute the invention hereof.
More specifically, the present invention relates to an improved poppet-type valve unit having an improved poppet configuration so as to provide increased flow capability and/or minimal valve member stroke between open and closed positions, in comparison to prior poppet-type valve units, such as the units of the aforementioned patents.
More specifically, in the improved poppet-type valve unit of the present invention, the annular elastomeric poppet cooperates with an annular valve seat, but the poppet is provided with an exterior profile which enables the flow area between the poppet and valve seat, in the open position, to be maximized in relationship to the stroke of the valve member between open and closed positions, thereby providing for increased flow capability in proportion to valve stroke.
In the improved poppet-type valve unit, as aforesaid, the poppet has an exterior profile defined by a pair of generally frusto-conical surfaces which are disposed radially inwardly and outwardly with respect to one another so that the inner frusto-conical surface terminates in an outer diameter which substantially corresponds with the inner diameter of the outer frusto-conical surface. The inner frusto-conical surface extends at a steeper angle or slope relative to valve movement direction than does the outer frusto-conical surface, thereby defining a peak or corner where the two frusto-conical surfaces meet. This peak substantially corresponds in diameter to the diameter of the valve seat and is substantially contacted by the valve seat when the poppet is sealed against the valve seat. This maximizes the flow area between the poppet and the valve seat when the poppet is opened, and in addition maximizes the amount of elastomeric material disposed in the region contacted by the valve seat to maximize the sealing engagement.